Version 2.03RC2 provisional

Use new Wire library form CoreNG
Use a separate task to keep DueX endstop input status up to date
Task priority definitions moved from RRFLibraries project to ReprapFirmware.h
Added folder src/Hardware and moved some files into it

29 files changed, 237 insertions, 119 deletions

diff --git a/.project b/.project
index c1983b6b..f47c0375 100644
--- a/.project
+++ b/.project
@@ -4,8 +4,8 @@
 	<comment></comment>
 	<projects>
 		<project>CoreNG</project>
-		<project>FreeRTOS</project>
 		<project>RRFLibraries</project>
+		<project>FreeRTOS</project>
 	</projects>
 	<buildSpec>
 		<buildCommand>
diff --git a/src/BugList.txt b/src/BugList.txt
index ba594e4a..d88c66ea 100644
--- a/src/BugList.txt
+++ b/src/BugList.txt
@@ -135,8 +135,8 @@ Menu.cpp
 MenuItem.h, cpp
 
 Planned for 2.03:
-- I2C errors: can we recover from them?
-- check: is stop.g always run at end of SD print, not just in response to M0?
+- [done, community to test] I2C errors: recover from them
+- [done, ok] Separate task to keep DuetX endstop input state up to date
 - [ok] check: start.g should not be run when resurrecting a print
 
 - [on hold] investigate filament file not run on initial tool change, https://forum.duet3d.com/topic/9405/first-t0-in-gcode-does-not-work/5
diff --git a/src/CAN/CanSender.cpp b/src/CAN/CanSender.cpp
index e4ecf7c9..7f98db3f 100644
--- a/src/CAN/CanSender.cpp
+++ b/src/CAN/CanSender.cpp
@@ -379,7 +379,7 @@ void CanSender::Init()
 	configure_mcan();
 
 	// Create the task that sends CAN messages
-	canSenderTask.Create(CanSenderLoop, "CanSender", nullptr, TaskBase::CanSenderPriority);
+	canSenderTask.Create(CanSenderLoop, "CanSender", nullptr, TaskPriority::CanSenderPriority);
 }
 
 // Add a buffer to the end of the send queue
diff --git a/src/Display/Display.cpp b/src/Display/Display.cpp
index 37dc7c20..3037737b 100644
--- a/src/Display/Display.cpp
+++ b/src/Display/Display.cpp
@@ -11,7 +11,7 @@
 
 #include "GCodes/GCodes.h"
 #include "GCodes/GCodeBuffer.h"
-#include "IoPorts.h"
+#include "Hardware/IoPorts.h"
 #include "Pins.h"
 
 constexpr int DefaultPulsesPerClick = -4;			// values that work with displays I have are 2 and -4
diff --git a/src/Display/RotaryEncoder.cpp b/src/Display/RotaryEncoder.cpp
index c4ba8f6c..69273719 100644
--- a/src/Display/RotaryEncoder.cpp
+++ b/src/Display/RotaryEncoder.cpp
@@ -3,7 +3,7 @@
 #if SUPPORT_12864_LCD
 
 #include "Pins.h"
-#include "IoPorts.h"
+#include "Hardware/IoPorts.h"
 
 RotaryEncoder::RotaryEncoder(Pin p0, Pin p1, Pin pb)
 	: pin0(p0), pin1(p1), pinButton(pb), ppc(1), encoderChange(0), encoderState(0), newPress(false), reverseDirection(false) {}
diff --git a/src/DuetNG/DueXn.cpp b/src/DuetNG/DueXn.cpp
index 3b4b745f..b415e66e 100644
--- a/src/DuetNG/DueXn.cpp
+++ b/src/DuetNG/DueXn.cpp
@@ -10,16 +10,17 @@
 #include "Platform.h"
 #include "RepRap.h"
 #include "Wire.h"
+#include "Hardware/I2C.h"
 
 namespace DuetExpansion
 {
-	const uint8_t DueXnAddress = 0x3E;					// address of the SX1509B on the DueX2/DueX5
+	constexpr uint8_t DueXnAddress = 0x3E;						// address of the SX1509B on the DueX2/DueX5
+	static constexpr unsigned int DueXTaskStackWords = 100;		// task stack size in dwords
 
 	static SX1509 dueXnExpander;
 	static uint16_t dueXnInputMask;
 	static uint16_t dueXnInputBits = 0;
 	static ExpansionBoardType dueXnBoardType = ExpansionBoardType::none;
-	static volatile bool dueXstateChanged = false;
 
 	const uint8_t AdditionalIoExpanderAddress = 0x71;	// address of the SX1509B we allow for general I/O expansion
 
@@ -27,6 +28,11 @@ namespace DuetExpansion
 	static bool additionalIoExpanderPresent = false;
 	static uint16_t additionalIoInputBits = 0;
 
+	static volatile bool taskWaiting = false;
+	static volatile bool inputsChanged = false;
+
+	Task<DueXTaskStackWords> *dueXTask = nullptr;
+
 	// The original DueX2 and DueX5 boards had 2 board ID pins, bits 14 and 15.
 	// The new ones use bit 15 for fan 8, so not we just have bit 14.
 	// If we want any more variants, they will have to use a different I2C address.
@@ -56,15 +62,44 @@ namespace DuetExpansion
 	const unsigned int Gpio4Bit = 8;
 	const uint16_t AllGpioBits = (1u << Gpio1Bit) | (1u << Gpio2Bit) | (1u << Gpio3Bit) | (1u <<Gpio4Bit);
 
+	// ISR for when the SX1509B on the DueX indicates that the state of an input has changed.
+	// Note, we must only wake up the DueX task if it is waiting on this specific interrupt.
+	// Otherwise we might wake it prematurely when it is waiting for an I2C transaction to be completed.
 	static void DueXIrq(CallbackParameter p)
 	{
-		dueXstateChanged = true;
+		inputsChanged = true;
+		if (taskWaiting)
+		{
+			taskWaiting = false;
+			dueXTask->GiveFromISR();
+		}
+	}
+
+	extern "C" [[noreturn]] void DueXTask(void * pvParameters)
+	{
+		for (;;)
+		{
+			inputsChanged = false;
+			dueXnInputBits = dueXnExpander.digitalReadAll();
+
+			cpu_irq_disable();
+			if (!inputsChanged)
+			{
+				taskWaiting = true;
+				cpu_irq_enable();
+				TaskBase::Take();
+			}
+			else
+			{
+				cpu_irq_enable();
+			}
+		}
 	}
 
 	// Identify which expansion board (if any) is attached and initialise it
 	ExpansionBoardType DueXnInit()
 	{
-		reprap.GetPlatform().InitI2c();						// initialise I2C
+		I2C::Init();										// initialise I2C
 
 		// DC 2018-07-12: occasionally the SX1509B isn't found after doing a software reset, so try a few more attempts
 		bool ret;
@@ -103,8 +138,10 @@ namespace DuetExpansion
 			attachInterrupt(DueX_INT, DueXIrq, InterruptMode::INTERRUPT_MODE_FALLING, nullptr);
 
 			// Clear any initial interrupts
-			(void)dueXnExpander.interruptSource(true);
-			dueXnInputBits = dueXnExpander.digitalReadAll();
+			(void)dueXnExpander.interruptSourceAndClear();
+
+			dueXTask = new Task<DueXTaskStackWords>();
+			dueXTask->Create(DueXTask, "DUEX", nullptr, TaskPriority::DueXPriority);
 		}
 
 		return dueXnBoardType;
@@ -113,7 +150,7 @@ namespace DuetExpansion
 	// Look for an additional output pin expander
 	void AdditionalOutputInit()
 	{
-		reprap.GetPlatform().InitI2c();						// initialise I2C
+		I2C::Init();										// initialise I2C
 
 		bool ret;
 		unsigned int attempts = 0;
@@ -155,20 +192,6 @@ namespace DuetExpansion
 		return (additionalIoExpanderPresent) ? "SX1509B expander" : nullptr;
 	}
 
-	// Update the input bits. The purpose of this is so that the step interrupt can pick up values that are fairly up-to-date,
-	// even though it is not safe for it to call expander.digitalReadAll(). When we move to RTOS, this will be a high priority task.
-	void Spin()
-	{
-		if (dueXnBoardType != ExpansionBoardType::none && dueXstateChanged && !inInterrupt() && __get_BASEPRI() == 0)
-		{
-			// Interrupt occurred, so input data may have changed
-			dueXstateChanged = false;
-			dueXnInputBits = dueXnExpander.digitalReadAll();
-		}
-
-		// We don't have an interrupt from the additional I/O expander, so we don't poll it here
-	}
-
 	// Set the I/O mode of a pin
 	void SetPinMode(Pin pin, PinMode mode)
 	{
diff --git a/src/DuetNG/DueXn.h b/src/DuetNG/DueXn.h
index bdd479c3..cc78db90 100644
--- a/src/DuetNG/DueXn.h
+++ b/src/DuetNG/DueXn.h
@@ -31,7 +31,6 @@ namespace DuetExpansion
 	void DigitalWrite(Pin pin, bool high);						// Write a pin
 	void AnalogOut(Pin pin, float pwm);							// Set the PWM value on this pin
 	uint16_t DiagnosticRead();									// Diagnose the SX1509 by setting all pins as inputs and reading them
-	void Spin();												// Task to keep the endstop inputs up to date
 	void Diagnostics(MessageType mtype);						// Print diagnostic data
 };
 
diff --git a/src/DuetNG/SX1509.cpp b/src/DuetNG/SX1509.cpp
index 9c8bb129..a3412874 100644
--- a/src/DuetNG/SX1509.cpp
+++ b/src/DuetNG/SX1509.cpp
@@ -22,17 +22,17 @@ Distributed as-is; no warranty is given.
 ******************************************************************************/
 
 #include "RepRapFirmware.h"
-#include "Wire.h"
 #include "Tasks.h"
 #include "SX1509.h"
 #include "SX1509Registers.h"
-#include "RTOSIface/RTOSIface.h"
+#include "Hardware/I2C.h"
 
 SX1509::SX1509() : _clkX(0)
 {
 }
 
-//************* Public functions. These must all acquire and release the I2C mutex around any I2C transactions. ***********
+// Public functions
+// Any operation requiring multiple I2C transactions must acquire and release the I2C mutex around them.
 
 // Test for the presence of a SX1509B. The I2C subsystem must be initialised before calling this.
 bool SX1509::begin(uint8_t address)
@@ -156,26 +156,24 @@ void SX1509::pinModeMultiple(uint16_t pins, PinMode inOut)
 
 void SX1509::digitalWrite(uint8_t pin, bool highLow)
 {
-	MutexLocker lock(Tasks::GetI2CMutex());
-
 	if (((1u << pin) & pwmPins) != 0)
 	{
 		analogWrite(pin, (highLow) ? 255 : 0);
 	}
 	else if (highLow)
 	{
+		MutexLocker lock(Tasks::GetI2CMutex());
 		setBitsInWord(REG_DATA_B, 1u << pin);
 	}
 	else
 	{
+		MutexLocker lock(Tasks::GetI2CMutex());
 		clearBitsInWord(REG_DATA_B, 1u << pin);
 	}
 }
 
 bool SX1509::digitalRead(uint8_t pin)
 {
-	MutexLocker lock(Tasks::GetI2CMutex());
-
 	if (pin >= 8)
 	{
 		return (readByte(REG_DATA_B) & (1u << (pin - 8))) != 0;
@@ -188,8 +186,6 @@ bool SX1509::digitalRead(uint8_t pin)
 
 uint16_t SX1509::digitalReadAll()
 {
-	MutexLocker lock(Tasks::GetI2CMutex());
-
 	return readWord(REG_DATA_B);
 }
 
@@ -240,8 +236,6 @@ void SX1509::ledDriverInitMultiple(uint16_t pins, bool log, bool openDrain)
 
 void SX1509::analogWrite(uint8_t pin, uint8_t iOn)
 {
-	MutexLocker lock(Tasks::GetI2CMutex());
-
 	// Write the on intensity of pin
 	// Linear mode: Ion = iOn
 	// Log mode: Ion = f(iOn)
@@ -292,23 +286,26 @@ void SX1509::enableInterruptMultiple(uint16_t pins, uint8_t riseFall)
 	}
 
 	writeDword(REG_SENSE_HIGH_B, pinMask);
-
 	clearBitsInWord(REG_INTERRUPT_MASK_B, pins);
 }
 
-uint16_t SX1509::interruptSource(bool clear)
+uint16_t SX1509::interruptSource()
 {
-	const uint16_t intSource = readWord(REG_INTERRUPT_SOURCE_B);
-	if (clear)
-	{
-		writeWord(REG_INTERRUPT_SOURCE_B, 0xFFFF);	// Clear interrupts
-	}
+	return readWord(REG_INTERRUPT_SOURCE_B);
+}
+
+uint16_t SX1509::interruptSourceAndClear()
+{
+	MutexLocker lock(Tasks::GetI2CMutex());
+
+	const uint16_t intSource = interruptSource();
+	writeWord(REG_INTERRUPT_SOURCE_B, intSource);	// Clear interrupts
 	return intSource;
 }
 
 bool SX1509::checkInterrupt(uint8_t pin)
 {
-	return (interruptSource(false) & (1u << pin)) != 0;
+	return (interruptSource() & (1u << pin)) != 0;
 }
 
 //********* Private functions. The I2C mutex must be owned by the caller. ***********
@@ -413,7 +410,7 @@ uint8_t SX1509::readByte(uint8_t registerAddress)
 {
 	uint8_t data[2];
 	data[0] = registerAddress;
-	if (I2C_IFACE.Transfer(deviceAddress, data, 1, 1) == 2)
+	if (I2C::Transfer(deviceAddress, data, 1, 1) == 2)
 	{
 		return data[1];
 	}
@@ -429,7 +426,7 @@ uint16_t SX1509::readWord(uint8_t registerAddress)
 {
 	uint8_t data[3];
 	data[0] = registerAddress;
-	if (I2C_IFACE.Transfer(deviceAddress, data, 1, 2) == 3)
+	if (I2C::Transfer(deviceAddress, data, 1, 2) == 3)
 	{
 		return (data[1] << 8) | data[2];
 	}
@@ -445,7 +442,7 @@ uint32_t SX1509::readDword(uint8_t registerAddress)
 {
 	uint8_t data[5];
 	data[0] = registerAddress;
-	if (I2C_IFACE.Transfer(deviceAddress, data, 1, 4) == 5)
+	if (I2C::Transfer(deviceAddress, data, 1, 4) == 5)
 	{
 		return (data[1] << 24) | (data[2] << 16) | (data[3] << 8) | data[4];
 	}
@@ -460,7 +457,7 @@ uint32_t SX1509::readDword(uint8_t registerAddress)
 void SX1509::writeByte(uint8_t registerAddress, uint8_t writeValue)
 {
 	uint8_t data[2] = { registerAddress, writeValue };
-	(void)I2C_IFACE.Transfer(deviceAddress, data, 2, 0);
+	(void)I2C::Transfer(deviceAddress, data, 2, 0);
 }
 
 // writeWord(uint8_t registerAddress, uint16_t writeValue)
@@ -471,7 +468,7 @@ void SX1509::writeByte(uint8_t registerAddress, uint8_t writeValue)
 void SX1509::writeWord(uint8_t registerAddress, uint16_t writeValue)
 {
 	uint8_t data[3] = { registerAddress, (uint8_t)(writeValue >> 8), (uint8_t)writeValue };
-	(void)I2C_IFACE.Transfer(deviceAddress, data, 3, 0);
+	(void)I2C::Transfer(deviceAddress, data, 3, 0);
 }
 
 // writeDword(uint8_t registerAddress, uint32_t writeValue)
@@ -480,7 +477,7 @@ void SX1509::writeWord(uint8_t registerAddress, uint16_t writeValue)
 void SX1509::writeDword(uint8_t registerAddress, uint32_t writeValue)
 {
 	uint8_t data[5] = { registerAddress, (uint8_t)(writeValue >> 24), (uint8_t)(writeValue >> 16), (uint8_t)(writeValue >> 8), (uint8_t)writeValue };
-	(void)I2C_IFACE.Transfer(deviceAddress, data, 5, 0);
+	(void)I2C::Transfer(deviceAddress, data, 5, 0);
 }
 
 // End
diff --git a/src/DuetNG/SX1509.h b/src/DuetNG/SX1509.h
index 64587c5c..41ebfe00 100644
--- a/src/DuetNG/SX1509.h
+++ b/src/DuetNG/SX1509.h
@@ -233,11 +233,9 @@ public:
 	//	Output: 16-bit value, with a single bit set representing the pin(s) that
 	//		generated an interrupt. E.g. a return value of	0x0104 would mean pins 8
 	//		and 3 (bits 8 and 3) have generated an interrupt.
-	//  Input:
-	//  	- clear: boolean commanding whether the interrupt should be cleared
-	//  	  after reading or not.
 	// -----------------------------------------------------------------------------
-	uint16_t interruptSource(bool clear);
+	uint16_t interruptSource();
+	uint16_t interruptSourceAndClear();
 
 	// -----------------------------------------------------------------------------
 	// checkInterrupt(void): Checks if a single pin generated an interrupt.
diff --git a/src/GCodes/GCodes3.cpp b/src/GCodes/GCodes3.cpp
index 36a60cf4..2e2afd24 100644
--- a/src/GCodes/GCodes3.cpp
+++ b/src/GCodes/GCodes3.cpp
@@ -15,6 +15,7 @@
 #include "Tools/Tool.h"
 #include "PrintMonitor.h"
 #include "Tasks.h"
+#include "Hardware/I2C.h"
 
 #if HAS_WIFI_NETWORKING
 # include "FirmwareUpdater.h"
@@ -1059,12 +1060,8 @@ GCodeResult GCodes::SendI2c(GCodeBuffer& gb, const StringRef &reply)
 				bValues[i] = (uint8_t)values[i];
 			}
 
-			platform.InitI2c();
-			size_t bytesTransferred;
-			{
-				MutexLocker lock(Tasks::GetI2CMutex());
-				bytesTransferred = I2C_IFACE.Transfer(address, bValues, numToSend, numToReceive);
-			}
+			I2C::Init();
+			const size_t bytesTransferred = I2C::Transfer(address, bValues, numToSend, numToReceive);
 
 			if (bytesTransferred < numToSend)
 			{
@@ -1109,14 +1106,10 @@ GCodeResult GCodes::ReceiveI2c(GCodeBuffer& gb, const StringRef &reply)
 			const uint32_t numBytes = gb.GetUIValue();
 			if (numBytes > 0 && numBytes <= MaxI2cBytes)
 			{
-				platform.InitI2c();
+				I2C::Init();
 
 				uint8_t bValues[MaxI2cBytes];
-				size_t bytesRead;
-				{
-					MutexLocker lock(Tasks::GetI2CMutex());
-					bytesRead = I2C_IFACE.Transfer(address, bValues, 0, numBytes);
-				}
+				const size_t bytesRead = I2C::Transfer(address, bValues, 0, numBytes);
 
 				reply.copy("Received");
 				if (bytesRead == 0)
diff --git a/src/DmacManager.cpp b/src/Hardware/DmacManager.cpp
index d11a92f0..d11a92f0 100644
--- a/src/DmacManager.cpp
+++ b/src/Hardware/DmacManager.cpp
diff --git a/src/DmacManager.h b/src/Hardware/DmacManager.h
index 23a3c328..23a3c328 100644
--- a/src/DmacManager.h
+++ b/src/Hardware/DmacManager.h
diff --git a/src/Hardware/I2C.cpp b/src/Hardware/I2C.cpp
new file mode 100644
index 00000000..9db08524
--- /dev/null
+++ b/src/Hardware/I2C.cpp
@@ -0,0 +1,66 @@
+/*
+ * I2C.cpp
+ *
+ *  Created on: 13 May 2019
+ *      Author: David
+ */
+
+#include "I2C.h"
+#include "Tasks.h"
+
+#if defined(I2C_IFACE)
+static bool i2cInitialised = false;
+#endif
+
+// Initialise the I2C interface, if not already done
+void I2C::Init()
+{
+#if defined(I2C_IFACE)
+	if (!i2cInitialised)
+	{
+		MutexLocker lock(Tasks::GetI2CMutex());
+		if (!i2cInitialised)			// test it again, now that we own the mutex
+		{
+			I2C_IFACE.BeginMaster(I2cClockFreq);
+			i2cInitialised = true;
+		}
+	}
+#endif
+}
+
+#if defined(I2C_IFACE) && defined(RTOS)
+
+#include "RTOSIface/RTOSIface.h"
+
+static TaskHandle_t twiTask = nullptr;				// the task that is waiting for a TWI command to complete
+
+extern "C" void WIRE_ISR_HANDLER()
+{
+	WIRE_INTERFACE->TWI_IDR = 0xFFFFFFFF;
+	if (twiTask != nullptr)
+	{
+		BaseType_t higherPriorityTaskWoken = pdFALSE;
+		vTaskNotifyGiveFromISR(twiTask, &higherPriorityTaskWoken);	// wake up the task
+		twiTask = nullptr;
+		portYIELD_FROM_ISR(higherPriorityTaskWoken);
+	}
+}
+
+uint32_t I2C::statusWaitFunc(Twi *twi, uint32_t bitsToWaitFor)
+{
+	uint32_t sr = twi->TWI_SR;
+	if ((sr & bitsToWaitFor) == 0)
+	{
+		// Suspend this task until we get an interrupt indicating that a status bit that we are interested in has been set
+		twiTask = xTaskGetCurrentTaskHandle();
+		twi->TWI_IER = bitsToWaitFor;
+		(void)TaskBase::Take(2);
+		sr = twi->TWI_SR;
+		twi->TWI_IDR = 0xFFFFFFFF;
+	}
+	return sr;
+}
+
+#endif
+
+// End
diff --git a/src/Hardware/I2C.h b/src/Hardware/I2C.h
new file mode 100644
index 00000000..46fe135f
--- /dev/null
+++ b/src/Hardware/I2C.h
@@ -0,0 +1,48 @@
+/*
+ * I2C.h
+ *
+ *  Created on: 13 May 2019
+ *      Author: David
+ */
+
+#ifndef SRC_HARDWARE_I2C_H_
+#define SRC_HARDWARE_I2C_H_
+
+#include "Wire.h"
+#include "RepRapFirmware.h"
+#include "Tasks.h"
+
+namespace I2C
+{
+	void Init();
+
+#ifdef I2C_IFACE
+
+#ifdef RTOS
+
+	uint32_t statusWaitFunc(Twi *twi, uint32_t bitsToWaitFor);
+
+	// Transfer data to/from an I2C peripheral.
+	// If the caller needs to do multiple I2C transactions without being interrupted, it should own the i2C mutex before calling this.
+	// Otherwise the caller need nort own the mutex because it will be acquired here.
+	inline size_t Transfer(uint16_t address, uint8_t *buffer, size_t numToWrite, size_t numToRead)
+	{
+		MutexLocker Lock(Tasks::GetI2CMutex());
+		return I2C_IFACE.Transfer(address, buffer, numToWrite, numToRead, statusWaitFunc);
+	}
+
+#else
+
+	// Transfer data to/from an I2C peripheral
+	inline size_t Transfer(uint16_t address, uint8_t *buffer, size_t numToWrite, size_t numToRead)
+	{
+		return I2C_IFACE.Transfer(address, buffer, numToWrite, numToRead);
+	}
+
+#endif
+
+#endif
+
+}
+
+#endif /* SRC_HARDWARE_I2C_H_ */
diff --git a/src/IoPorts.cpp b/src/Hardware/IoPorts.cpp
index 0fb1605d..0fb1605d 100644
--- a/src/IoPorts.cpp
+++ b/src/Hardware/IoPorts.cpp
diff --git a/src/IoPorts.h b/src/Hardware/IoPorts.h
index 9570e72c..9570e72c 100644
--- a/src/IoPorts.h
+++ b/src/Hardware/IoPorts.h
diff --git a/src/Heating/Heat.cpp b/src/Heating/Heat.cpp
index cd852262..8362c3e1 100644
--- a/src/Heating/Heat.cpp
+++ b/src/Heating/Heat.cpp
@@ -154,7 +154,7 @@ void Heat::Init()
 	coldExtrude = false;
 
 #ifdef RTOS
-	heaterTask.Create(HeaterTask, "HEAT", nullptr, TaskBase::HeatPriority);
+	heaterTask.Create(HeaterTask, "HEAT", nullptr, TaskPriority::HeatPriority);
 #else
 	lastTime = millis() - HeatSampleIntervalMillis;		// flag the PIDS as due for spinning
 	active = true;
diff --git a/src/Heating/Sensors/DhtSensor.cpp b/src/Heating/Sensors/DhtSensor.cpp
index fa255901..51af304e 100644
--- a/src/Heating/Sensors/DhtSensor.cpp
+++ b/src/Heating/Sensors/DhtSensor.cpp
@@ -9,7 +9,7 @@
 #include "RepRap.h"
 #include "GCodes/GCodeBuffer.h"
 #include "Movement/StepTimer.h"
-#include "IoPorts.h"
+#include "Hardware/IoPorts.h"
 
 #if SUPPORT_DHT_SENSOR
 
@@ -137,7 +137,7 @@ DhtSensorHardwareInterface *DhtSensorHardwareInterface::Create(unsigned int rela
 	if (dhtTask == nullptr)
 	{
 		dhtTask = new Task<DhtTaskStackWords>;
-		dhtTask->Create(DhtTask, "DHTSENSOR", nullptr, TaskBase::HeatPriority);
+		dhtTask->Create(DhtTask, "DHTSENSOR", nullptr, TaskPriority::DhtPriority);
 	}
 
 	return activeSensors[relativeChannel];
diff --git a/src/Heating/Sensors/DhtSensor.h b/src/Heating/Sensors/DhtSensor.h
index 37eb0472..0263b7c0 100644
--- a/src/Heating/Sensors/DhtSensor.h
+++ b/src/Heating/Sensors/DhtSensor.h
@@ -48,7 +48,7 @@ private:
 	void TakeReading();
 	TemperatureError ProcessReadings();
 
-	static constexpr uint32_t DhtTaskStackWords = 100;		// task stack size in dwords. 80 was not enough. Use 300 if debugging is enabled.
+	static constexpr unsigned int DhtTaskStackWords = 100;		// task stack size in dwords. 80 was not enough. Use 300 if debugging is enabled.
 	static Mutex dhtMutex;
 	static Task<DhtTaskStackWords> *dhtTask;
 	static DhtSensorHardwareInterface *activeSensors[MaxSpiTempSensors];
diff --git a/src/Movement/StepperDrivers/TMC51xx.cpp b/src/Movement/StepperDrivers/TMC51xx.cpp
index 3bf3d676..2613793f 100644
--- a/src/Movement/StepperDrivers/TMC51xx.cpp
+++ b/src/Movement/StepperDrivers/TMC51xx.cpp
@@ -12,7 +12,7 @@
 #if SUPPORT_TMC51xx
 
 #include "RTOSIface/RTOSIface.h"
-#include <Movement/Move.h>
+#include "Movement/Move.h"
 
 #ifdef SAME51
 # include "HAL/IoPorts.h"
@@ -20,7 +20,7 @@
 # include "peripheral_clk_config.h"
 # include "HAL/SAME5x.h"
 #elif SAME70
-# include "DmacManager.h"
+# include "Hardware/DmacManager.h"
 #endif
 
 //#define TMC_TYPE	5130
@@ -1289,7 +1289,7 @@ namespace SmartDrivers
 		xdmac_enable_interrupt(XDMAC, DmacChanTmcRx);
 #endif
 
-		tmcTask.Create(TmcLoop, "TMC", nullptr, TaskBase::TmcPriority);
+		tmcTask.Create(TmcLoop, "TMC", nullptr, TaskPriority::TmcPriority);
 	}
 
 	void SetAxisNumber(size_t driver, uint32_t axisNumber)
diff --git a/src/Networking/Network.cpp b/src/Networking/Network.cpp
index 6f3557d5..c0217380 100644
--- a/src/Networking/Network.cpp
+++ b/src/Networking/Network.cpp
@@ -274,7 +274,7 @@ void Network::Activate()
 	}
 
 #ifdef RTOS
-	networkTask.Create(NetworkLoop, "NETWORK", nullptr, TaskBase::SpinPriority);
+	networkTask.Create(NetworkLoop, "NETWORK", nullptr, TaskPriority::SpinPriority);
 #endif
 
 }
diff --git a/src/Platform.cpp b/src/Platform.cpp
index 1edfb007..eb7160bb 100644
--- a/src/Platform.cpp
+++ b/src/Platform.cpp
@@ -35,9 +35,9 @@
 #include "SoftTimer.h"
 #include "Logger.h"
 #include "Tasks.h"
-#include "DmacManager.h"
+#include "Hardware/DmacManager.h"
 #include "Math/Isqrt.h"
-#include "Wire.h"
+#include "Hardware/I2C.h"
 
 #ifndef __LPC17xx__
 # include "sam/drivers/tc/tc.h"
@@ -166,13 +166,13 @@ extern "C" void UrgentInit()
 
 uint8_t Platform::softwareResetDebugInfo = 0;			// extra info for debugging
 
-Platform::Platform() :
-		logger(nullptr), board(DEFAULT_BOARD_TYPE), active(false), errorCodeBits(0),
+Platform::Platform()
+	: logger(nullptr), board(DEFAULT_BOARD_TYPE), active(false), errorCodeBits(0),
 #if HAS_SMART_DRIVERS
-		nextDriveToPoll(0),
+	  nextDriveToPoll(0),
 #endif
-		lastFanCheckTime(0), auxGCodeReply(nullptr), sysDir(nullptr), tickState(0), debugCode(0),
-		lastWarningMillis(0), deliberateError(false), i2cInitialised(false)
+	  lastFanCheckTime(0), auxGCodeReply(nullptr), sysDir(nullptr), tickState(0), debugCode(0),
+	  lastWarningMillis(0), deliberateError(false)
 {
 	massStorage = new MassStorage(this);
 }
@@ -292,7 +292,7 @@ void Platform::Init()
 	ARRAY_INIT(defaultMacAddress, DefaultMacAddress);
 
 	// Motor current setting on Duet 0.6 and 0.8.5
-	InitI2c();
+	I2C::Init();
 	mcpExpansion.setMCP4461Address(0x2E);		// not required for mcpDuet, as this uses the default address
 	ARRAY_INIT(potWipes, POT_WIPES);
 	senseResistor = SENSE_RESISTOR;
@@ -2356,8 +2356,8 @@ void Platform::Diagnostics(MessageType mtype)
 
 #ifdef I2C_IFACE
 	const TwoWire::ErrorCounts errs = I2C_IFACE.GetErrorCounts(true);
-	MessageF(mtype, "I2C nak errors %" PRIu32 ", send timeouts %" PRIu32 ", receive timeouts %" PRIu32 ", finishTimeouts %" PRIu32 "\n",
-		errs.naks, errs.sendTimeouts, errs.recvTimeouts, errs.finishTimeouts);
+	MessageF(mtype, "I2C nak errors %" PRIu32 ", send timeouts %" PRIu32 ", receive timeouts %" PRIu32 ", finishTimeouts %" PRIu32 ", resets %" PRIu32 "\n",
+		errs.naks, errs.sendTimeouts, errs.recvTimeouts, errs.finishTimeouts, errs.resets);
 #endif
 }
 
@@ -4782,22 +4782,6 @@ bool Platform::SetDateTime(time_t time)
 	return ok;
 }
 
-// Initialise the I2C interface, if not already done
-void Platform::InitI2c()
-{
-#if defined(I2C_IFACE)
-	if (!i2cInitialised)
-	{
-		MutexLocker lock(Tasks::GetI2CMutex());
-		if (!i2cInitialised)			// test it again, now that we own the mutex
-		{
-			I2C_IFACE.BeginMaster(I2cClockFreq);
-			i2cInitialised = true;
-		}
-	}
-#endif
-}
-
 #if SAM4E || SAM4S || SAME70
 
 // Get a pseudo-random number
diff --git a/src/Platform.h b/src/Platform.h
index 0a5fde72..c511e00e 100644
--- a/src/Platform.h
+++ b/src/Platform.h
@@ -29,7 +29,7 @@ Licence: GPL
 // Platform-specific includes
 
 #include "RepRapFirmware.h"
-#include "IoPorts.h"
+#include "Hardware/IoPorts.h"
 #include "DueFlashStorage.h"
 #include "Fans/Fan.h"
 #include "Fans/Tacho.h"
@@ -610,7 +610,6 @@ public:
 	float GetLaserPwmFrequency() const { return laserPort.GetFrequency(); }
 
 	// Misc
-	void InitI2c();
 
 #if SAM4E || SAM4S || SAME70
 	uint32_t Random();
@@ -936,7 +935,6 @@ private:
 
 	// Misc
 	bool deliberateError;								// true if we deliberately caused an exception for testing purposes
-	bool i2cInitialised;								// true if the I2C subsystem has been initialised
 };
 
 // Where the htm etc files are
diff --git a/src/PortControl.h b/src/PortControl.h
index 455f2529..fd17527d 100644
--- a/src/PortControl.h
+++ b/src/PortControl.h
@@ -9,7 +9,7 @@
 #define SRC_PORTCONTROL_H_
 
 #include "RepRapFirmware.h"
-#include "IoPorts.h"			// for PinConfiguration
+#include "Hardware/IoPorts.h"			// for PinConfiguration
 
 class GCodeBuffer;
 
diff --git a/src/RepRap.cpp b/src/RepRap.cpp
index 76e42b34..70c48857 100644
--- a/src/RepRap.cpp
+++ b/src/RepRap.cpp
@@ -43,7 +43,7 @@ static_assert(CONF_HSMCI_XDMAC_CHANNEL == DmacChanHsmci, "mismatched DMA channel
 # include "task.h"
 
 # if SAME70
-#  include "DmacManager.h"
+#  include "Hardware/DmacManager.h"
 # endif
 
 // We call vTaskNotifyGiveFromISR from various interrupts, so the following must be true
@@ -409,12 +409,6 @@ void RepRap::Spin()
 	spinningModule = modulePrintMonitor;
 	printMonitor->Spin();
 
-#ifdef DUET_NG
-	ticksInSpinState = 0;
-	spinningModule = moduleDuetExpansion;
-	DuetExpansion::Spin();
-#endif
-
 	ticksInSpinState = 0;
 	spinningModule = moduleFilamentSensors;
 	FilamentMonitor::Spin();
diff --git a/src/RepRapFirmware.h b/src/RepRapFirmware.h
index 3483790c..e4e8f05a 100644
--- a/src/RepRapFirmware.h
+++ b/src/RepRapFirmware.h
@@ -335,6 +335,24 @@ constexpr float RadiansToDegrees = 180.0/3.141592653589793;
 typedef uint32_t FilePosition;
 const FilePosition noFilePosition = 0xFFFFFFFF;
 
+#ifdef RTOS
+
+// Task priorities
+namespace TaskPriority
+{
+	static constexpr int SpinPriority = 1;							// priority for tasks that rarely block
+	static constexpr int HeatPriority = 2;
+	static constexpr int DhtPriority = 2;
+	static constexpr int TmcPriority = 2;
+	static constexpr int AinPriority = 2;
+	static constexpr int DueXPriority = 3;
+	static constexpr int LaserPriority = 3;
+	static constexpr int CanSenderPriority = 3;
+	static constexpr int CanReceiverPriority = 3;
+}
+
+#endif
+
 //-------------------------------------------------------------------------------------------------
 // Interrupt priorities - must be chosen with care! 0 is the highest priority, 15 is the lowest.
 // This interacts with FreeRTOS config constant configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY which is currently defined as 3 for the SAME70 and 5 for the SAM4x.
diff --git a/src/Spindle.h b/src/Spindle.h
index 5e05993c..b1e7f3d2 100644
--- a/src/Spindle.h
+++ b/src/Spindle.h
@@ -9,7 +9,7 @@
 #define SPINDLE_H
 
 #include "RepRapFirmware.h"
-#include "IoPorts.h"
+#include "Hardware/IoPorts.h"
 
 class Spindle
 {
diff --git a/src/Tasks.cpp b/src/Tasks.cpp
index 545bddb9..abae4da6 100644
--- a/src/Tasks.cpp
+++ b/src/Tasks.cpp
@@ -137,7 +137,7 @@ extern "C" void AppMain()
 # endif
 
 	// Create the startup task
-	mainTask.Create(MainTask, "MAIN", nullptr, TaskBase::SpinPriority);
+	mainTask.Create(MainTask, "MAIN", nullptr, TaskPriority::SpinPriority);
 	vTaskStartScheduler();			// doesn't return
 }
 
diff --git a/src/Version.h b/src/Version.h
index 2c8274bc..14b3437a 100644
--- a/src/Version.h
+++ b/src/Version.h
@@ -11,16 +11,16 @@
 
 #ifndef VERSION
 #ifdef RTOS
-# define MAIN_VERSION	"2.03RC1+1"
+# define MAIN_VERSION	"2.03RC2"
 #else
-# define MAIN_VERSION	"1.24RC1+1"
+# define MAIN_VERSION	"1.24RC2"
 #endif
 
 # define VERSION MAIN_VERSION
 #endif
 
 #ifndef DATE
-# define DATE "2019-05-11b1"
+# define DATE "2019-05-14b2"
 #endif
 
 #define AUTHORS "reprappro, dc42, chrishamm, t3p3, dnewman, printm3d"